A rubber-modified vinyl-based graft copolymer resin such as acrylonitrile-butadiene-styrene (ABS) has good properties in terms of impact resistance, moldability, external appearance, and the like, and is broadly used in various fields including automobile components, electric/electronic products, office machinery, and the like.
In order to allow such a rubber-modified vinyl-based graft copolymer resin to be applied to interior/exterior materials for automobile components and electric/electronic products, the rubber-modified vinyl-based graft copolymer resin is required to exhibit good thermal resistance. In order to improve thermal resistance of the rubber-modified vinyl-based graft copolymer resin, a method of replacing part of components constituting the rubber-modified vinyl-based graft copolymer resin by a heat resistant copolymer has been developed. For example, a molded product produced by melt extrusion of a rubber-modified vinyl-based graft copolymer such as g-ABS together with a heat-resistant copolymer such as α-methylstyrene-styrene-acrylonitrile (AMS-SAN) and N-phenyl maleimide-styrene-acrylonitrile (PMI-SAN) is used.
However, the heat-resistant copolymer can cause problems such as gas generation due to depolymerization of α-methylstyrene and degradation in external appearance due to non-melting of N-phenyl maleimide, and exhibits low compatibility with the rubber-modified vinyl-based graft copolymer such as g-ABS, thereby causing deterioration and deviation in properties such as impact resistance and the like.
Therefore, there is a need for development of a rubber-modified vinyl-based graft copolymer, which can overcome problems caused by the heat-resistant copolymer and exhibit good properties in terms of impact resistance, thermal resistance and external appearance, and a thermoplastic resin composition including the same.
The background technique of the present invention is disclosed in U.S. Pat. No. 4,757,109 and the like.